Mercury emissions from the Deccan Traps may have played a role in the death of dinosaurs
[fusion_builder_container hundred_percent="no" equal_height_columns="no" hide_on_mobile="small-visibility,medium-visibility,large-visibility" background_position="center center" background_repeat="no-repeat" fade="no" background_parallax="none" parallax_speed="0.3" video_aspect_ratio="16:9" video_loop="yes" video_mute="yes" overlay_opacity="0.5" border_style="solid"][fusion_builder_row][fusion_builder_column type="1_1" layout="1_1" background_position="left top" background_color="" border_size="" border_color="" border_style="solid" border_position="all" spacing="yes" background_image="" background_repeat="no-repeat" padding="" margin_top="0px" margin_bottom="0px" class="" id="" animation_type="" animation_speed="0.3" animation_direction="left" hide_on_mobile="small-visibility,medium-visibility,large-visibility" center_content="no" last="no" min_height="" hover_type="none" link=""][fusion_text]The origin of the mass extinction which occurred at the end of the Cretaceous (limit Cretaceous-Tertiary -KT) and involved the death of dinosaurs is still matter of debate. The impact of a meteorite, in particular the impact of Chicxulub in the Yucatan Province (Mexico) is the most known theory. However, a recent study published in Geology by IDL's research Eric Font and an international team has shown the importance the volcanism of large scale, in specific the Deccan volcanism in India, might have had in the extinction in mass and dinosaur death.It is known that the impact of Chixulub and the Deccan volcanism happened almost simultaneously and in a very short time, at a geological scale. The scientific question relaunched by Eric Font’s article is “what was the relative contribution of each of the two catastrophic events - meteorite impact and large scale volcanism - in the KT mass extinction that lead to the dinosaur’s death?”The Deccan traps represent a surface of more than 106 km2 and they form lava mountains with more than 3500 meters high. While the nature and amount of greenhouse gases and acid aerosol liberated by the Deccan traps is relatively well described in the literature, much less is known about other toxic agents like mercury. Mercury has a long residence time in the atmosphere and thus it could have been easily transported around the globe, playing a significant role in the KT mass extinction. Here, the authors report anomalous concentrations of mercury in the KPg boundary at Bidart (France) within stratigraphic layers that are coeval with the most intense episode of the Deccan eruption. The Hg-enhanced level spans were detected in 1 meter thick sedimentary layers, where the KT limit is found. This interval also reveals high fragmentation indexes of planktic foraminiferal shells, interpreted as the result of ocean acidification, suggesting that Hg may have played a role in the KT mass extinction and the death of dinosaurs.The discovery of anomalous content of mercury in marine sediment from the Basque-Cantabric Basin (France) spanning the KT boundary provides evidence of the role played by the Deccan Traps in the KT mass extinction, and possibly in the death of dinosaurs.
Eric on 60- Second-Science, podcast da Scientific American ("Volcano Role in Dino Death Gets Mercury Boost")Some of the links to the national media coverage:ObservadorTVI24
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